In atomic absorption spectroscopy, the measurement of the absorption of a radiation beam at a characteristic resonant spectral line for a particular element yields a measure of the concentration of that element in an original sample solution. One of the most common techniques for atomizing an element for purposes of the absorption measurement is by introducing a liquid sample solution of the element of interest into a gas burner wherein droplets of the solution are vaporized and the element ultimately atomized, so as to form in the path of the apparatus radiation beam, a substantial quantity of the element of interest in its atomic state.
In order to effect appropriate burning of the element containing solution, the liquid must be converted into a fine spray and then mixed with a fuel and oxidant gas before introduction into the burner. The fine spray is achieved through the use of a nebulizer, such as described in U.S. Pat. No. 4,125,225, also assigned to the assignee herein.
A nebulizer, generally, employs a venturi-type restriction which passes rapidly moving gas (hereinafter referred to as an oxidant) past an opening, drawing a portion of the liquid sample solution into the gas stream, effecting an atomizing of the liquid in the process. The liquid is said to be aspirated by the venturi effect caused by the rapidly moving current of gas.
The sample laden gas or oxidant, then passes into the burner chamber where it is mixed with additional oxidant from an auxiliary inlet, and fuel such as acetylene. It is then introduced into the burner head where it is ignited.
The nebulizer of Pat. No. 4,125,225 is characterized by a capillary tubing which is a continuous corrosion-resistant single tube that extends all the way from its aspirated tip at one end to the liquid sample supply at the other end thereof. The present invention is directed to improvements over this prior art nebulizer, as will become clear as the description proceeds.